Hey guys, today when I went to go to a meeting for work I started the truck and it sputtered for a slight second then died. It will run when I give it gas but once I let off the pedal it dies. There isnt any check engine light or anything either. I dont think its a spark plug because wouldnt it sound different when running on 7 cylinders ? I know that because my old nissan sounded like a vw bug when a plug went out. Btw, I dont know if this matters but its the 5.2L manual.

 

Forgot to add. I decided to try out a spark plug tester my older brother inlaw left at the house. I connected the long end to the spark plug wire and then the other end to a spark plug that I knew worked off of my nissan when I changed the plugs on it. Well I had my younger brother inlaw crank it over and the spark plug tester shocked me! Well after I did that and reconnected the spark plug wire back into the sparkplug on the motor it started and it idled. I let it sit for a couple mins and decided to turn it off and restart it to make sure.. Well, it wouldnt idle again. Also, why did the spark plug tester shock me?

 

Electricity takes the path of least resistance. Which in this case, was you...... Most spark testers I have seen have a pretty fat gap. (lots of resistance.) You don't.

If you hold the gas a bit will it idle?

 

im having the same issue except when the truck is cold it starts fine if i drive to the store then start it again it revs up normal but when comming down to idle it drops and dies. when i start again i give it gas for about 30 seconds then let off easy its fine. mine is definately not spark because i just put plugs wires and distributer. i have also recently done the aic valve. ive tried different gas but no luck. mine is the v6. seems to do it only when motor is warm.

 

if there are no other problems (fuel, spark, skip, miss, timing, compression, etc), then the idle is controlled by 2 sensors that frequently misbehave. they are the TPS throttle position sensor, and the IAC idle air control.

tps is on drivers side of throttle body.
iac is on the back side.

do a search for a million posts about these stupid things. unfortunately, you can't search for short words, so try idle. the tps and iac interact with each other, and when one misbehaves, its difficult to tell which one it is, so you pretty much have to take your best guess. save your old part in case you guess wrong, and you can reuse it for your next guess in a couple of years.

if it idles ok with slight pressure on the gas pedal and dies when you let off, AND there are no TPS related check engine codes, then i'd guess the IAC. either part is about $40-50 at any local parts store. try one, then the other.

 

Well i started it back up again and it idles fine, but when i give it gas at 2k rpm or more it will dip down and die.

 

Might check fuel psi after reading that last post. IAC is easy to pull and clean. I use brake cleaner to clean plunger. Spay some on a rag and use finger to clean plunger seat were IAC goes. Sometime the black build up causes plunger to stick closed, open and slow plunger down for response. If this changes things A new IAC wouldn't be a bad purchase.

 

Well, I drove the truck around the block and it dies 3 times each time when I came to a stop. I went and parked it. I decided to get a bottle of lucas combustion lubricant/cleaner that goes into the fuel tank and pour some in. It started up great and the idle never dipped and the truck never died on me. Im wondering if it could be because I got a bad batch of gasoline, because the lucas stuff said that it helps neutralize bad fuel etc...

 

Entirely possible. Where did you get gas at last, and have you gotten gas there before? Was the station getting a delivery when you were getting gas?

 

I got it at a gas station called maverick. Ive gotten gas from there before and its fine. No i didnt see the fuel truck there when I was pumping. I think their unleaded fuel is 83 octane. which is what i use. I also noticed there was some water coming out of the tail pipe. not alot but it kinda misted onto the concrete. could it be because of the gas or because of the cold?